The boxelder tree in my yard grows a single, very large fungus every year. It is now falling off in chunks. I want to know if there is a certain variety that always grows on this type of tree? It is large, whitish, with prominent gills. My dog has gnawed on it and wants to do so again. Thank you. Karen in Billings, MT
Boxelder Trees are known to have weak, soft wood that is susceptible to pests and fungus issue.
The fungus you mention would be hard to identify without an image and even then there are many fungus.
You can take a sample to your County Extension to see if they can identify.
I would check with your vet on the concerns with your dog eating the fungus material.